Ink jet recording is a process of recording letters or drawings on the surface of a recording medium by ejecting an ink from a fine nozzle as droplets. As the ink jet recording process, a process of converting electric signals to mechanical signals using an electrostrictive element, and intermittently ejecting an ink reserved in a nozzle head section to record letters or symbols on the surface of a recording medium, a process rapidly heating a part of an ink reserved in a nozzle head section and positioned at very close to the ejecting portion to generate bubbles, and intermittently ejecting the ink by the volume expansion caused by the bubbles to record letters or symbols on the surface of a recording medium, etc., have been practically used.
As the ink supplying system in ink jet recording, a method of using an ink set comprising a combination of plural inks each having a different color is known. According to such an ink set, there is an advantage that the kind and the ejecting amount of each ink to be ejected from the ink set are selected from time to time according to a signal based on image information, thereby color images of high quality can be easily obtained.
As the inks for use in such an ink set, inks obtained by dissolving various kinds of water-soluble dyes in aqueous media are generally widely used, but recently, there have been provided inks obtained by dispersing pigments in aqueous media with the aid of dispersing agents. This is because inks using pigments (hereinafter, sometimes referred to as a pigment ink) have the feature of being excellent in weather resistance (water resistance, light resistance and the like) as compared with inks using water-soluble dyes.
However, with the ink set comprising pigment inks, which has hitherto been known, though high weather resistance can be obtained due to the use of the pigment inks, there are problems that the color reproducing range is insufficient and it is hard to reproduce images exactly. It is the current actual state that since an ink jet recording process has recently be given attention as a recording process that could take the place of photographs, an ink set comprising pigment inks which can attain further high image quality has been demanded.
The present invention is to solve the above-described problems, and an object thereof is to provide an ink set for ink jet recording and an ink jet recording process, which can not only obtain high weather resistance due to the use of pigment inks but also can obtain images having a high printed density and which have a wide color reproducing range.
Another object of the invention is to provide an ink jet recording process capable of performing text printing at a high printing density and with excellent abrasion resistance.
Still other object of the invention is to provide recorded matter having images formed at a high printed density and over a wide color reproducing range, and to provide text printed matter (recorded matter) having a high printed density and being excellent in abrasion resistance.